The present invention relates to an improved firing mechanism for firearms.
Previous methods for causing a projectile to be fired from a gun included use of a percussion activated primer and a hammer. When the hammer struck the primer, the primer fired, which in turn ignited gunpowder in the projectile. As a result, the projectile was propelled down the barrel and exited the gun.
In addition to mechanically firing a cartridge, previous methods also involved electrically firing a cartridge by using a battery, a switch and an electrically activated primer in the ammunition instead of a conventional hammer/firing pin arrangement. In those situations, the shooter pulled the trigger which acted upon the switch to connect the battery to the detonator and thus to cause the projectile to be fired. For example, U.S. Pat. No. 3,854,231 (Broyles) describes a small arms weapon in which the electrical power for firing the gun is provided by a rechargeable storage battery. In addition, provision is made, in the form of additional circuitry, for recharging the battery.
Likewise, U.S. Pat. No. 5,625,972 (King) teaches the use of a gun provided with an electronically fired cartridge. The cartridge or projectile located in the gun includes a chamber with an explosive and a primer cap with a heat activated primer. A fuse wire of appropriate electrical resistance extends through the primer for igniting the primer. It is connected in series with a switch and a battery. When the switch is closed, the circuit is completed causing electrical current to flow through the fuse wire. This causes the wire to heat up, thereby igniting the primer.
However, there are many problems associated with the use of a battery to supply the energy detonate the primer. First, the battery has limited life and, therefore, has to be either replaced or recharged periodically.
Second, the battery weighs a significant amount.
And third, batteries generate a low voltage (typically 9 volts) and a good electrical contact has to be made to both the case and to the primer electrode each time a new cartridge is loaded. As a result, firing reliability is adversely affected by corrosion, erosion, and a build-up of propellant residue as the gun ages and as more rounds are fired between cleanings.
Piezoelectric elements have been used in weapon systems. For example, U.S. Pat. No. No. 4,510,844 (Fritz) discloses a firing mechanism for handguns which uses a piezo-voltage generator as one of the sources of ignition energy. However, in order for the Fritz ignition system to work, the breech block piece 22 must be correctly positioned. Another difference between Fritz and the disclosed invention is that the striking piece 5 in Fritz moves in a linear, and not a circular path. Furthermore, although the Fritz patent says that energy from the piezo generator is delivered to a detonator, no detail is given as to how the detonator is activated.